SoftwareSerial mySerial(2, 3);
SoftwareSerial mySerial(10, 11);
http://arduino.cc/en/Reference/Serial"The Arduino Mega has three additional serial ports: Serial1 on pins 19 (RX) and 18 (TX), Serial2 on pins 17 (RX) and 16 (TX), Serial3 on pins 15 (RX) and 14 (TX). "With all those spare serial ports on the MEGA it is unnecessary to use SoftwareSerial which can conflict with other libraries.
In file included from Fingerprint_with_php110415.ino:40:0:/home/rizal/Downloads/Packages/arduino-1.6.3/libraries/FPS_GT511C3/FPS_GT511C3.h:13:28: fatal error: SoftwareSerial.h: No such file or directory #include "SoftwareSerial.h" ^compilation terminated.Error compiling.